* @exception org.omg.CosNaming.NamingContextPackage.InvalidName
*/
public String to_url (String addr, String sn) throws org.omg.CosNaming.NamingContextExtPackage.InvalidAddress, org.omg.CosNaming.NamingContextPackage.InvalidName {
// basic validation
if (addr == null || addr.length() == 0) {
throw new InvalidAddress();
}
if (sn == null || sn.length() == 0) {
throw new InvalidName();
}